Brake drum



April 4, 1939.

D. J. CAMPBELL BRAKE DRUM Filed Oct. 12, 1936 3 Sheets-Sheet 1 11V VENTOR Donald J. Camfibz/i ATTORNEY April 4, 1939. D. J. CAMPBELL BRAKE DRUM Filed Oct. 12, 1936 3 Sheets-Sheet 2 //v VENTOR Donald J. Cflffll'lbej/ A TTORNE Y April 4, 1939. D. J. CAMPBELL BRAKE DRUM Filed Oct. 12, 1956 5 Sheets-Sheet 3 /N VENTOR .Dalmfd J. Cam/zbdl M u. Em

A TTORNEY Patented Apr. 4,1939

UNITED STATES PATENT OFFICE BRAKE DRUM of Michigan Application October 12, 1938, Serial No. 105.293

1 Claim. (Cl. 188-218) My present invention relates to improvements in brake drums and particularly to brake drums of composite structure whereof a braking band of metal is cast into and fused to a supporting shell of steel and to the method of making such brake drums; and the principal objects of improvement are to provide a composite brake drum having not specifically enumerated are attained and will be apparent from a perusalof the following description when taken in connection with the accompanying drawings, in which:

Fig. 1 is a side'elevation of my composite brake drum.

Fig. 2 is a sectional view of the double width steel supporting shell of the brake drum. r

Fig. 3 is a side view of one of the heat transfer inserts employed.

Fig. 4 is a sectional view of a double width supporting shell having the heat transfer inserts in position within the angular corrugations of the supporting shell and illustrating the corrugation bending rollers in position as when starting to close the corrugations onto the heat transfer insert.

Fig. 5 is a sectional view as of Fig. 4 illustrating the corrugations closed against the heat transfer insert by the corrugation bending rollers.

Fig. 6 illustrates in section the double width brake drum supporting shell as during the operation of lining the same with molten metal.

Fig. 7 is a sectional view of a portion of a completed composite brake drum of my preferred structure, illustrating the heat transfer insert after it has been melted by the molten metal and again solidified. I

Fig. 8 is a sectional view of a modified structure as of Fig. 7 except therein the heat transfer insert has been cut and portions thereof bent against the inner periphery of the supporting shell.

Throughout the several views of the drawings similar numerals refer to similar parts, and

of the steel shell I having at one of its sides inwardly extending annular flange 2, axially extended flange portion}, hollow annular corrugations 4 in which are located heat transfer inserts 5 preferably of copper or of other non-ferrous 5 metal having a higher heat conduction factor than the steel of the supporting shell and that of the cast metal lining 6, which is machined at its radial side I to conform to suitable sealing means and at its inner periphery 8 to the required diameter for receiving any suitable braking shoes and mechanism and also to provide a smooth braking surface.

In Fig. 6 is illustrated a double width steel shell in the process of lining with molten metal, 9 representing a pouring box 'or ladle from which is being poured the molten metal ill to form, when cooled, the lining or braking band 6. During the process of lining, the steel shell. is preferably heated to a temperature that will prevent chilling of the molten metal as it is poured into the steel supporting shell which is then revolved while held concentric with the axis of rotation by taper chuck jaws H slidable in the conical bore of outer collet chuck member I 2 by spider l3 secured to slidable shaft l4 and also by annular head l5 secured to slidable shaft l 6.

In Fig. 4 is shown roller l'l pressing against the inner periphery of the supporting shell I and adjustable roller l8 in contact with the outer wall surface of the corrugations 4 as the operation of bending the walls of the corrugations to press the walls in against the heat transfer inserts 5 is begun. l9 represents clearance between the roller I1 and the inward radially extending flange 2 of 35 the shell l,,whereby as the corrugation walls are bent against the heat transfer inserts 5, the said flange 2 is permitted to move toward the roller l1 freely. In Fig. 5 the clearance I9 is less because the roller l8 has pressed the walls of the corrugations tightly against the sides of the heat transfer inserts and the flange 2 has consequently been drawn towards the roller H.

In the production of my present improved composite brake drun 1,I first provide the double width supporting shell l as by forming from sheet steel, with an inward radially extending flange 2 at each of its ends and intermediate the flanges 2 with a centrally located enlarged diameter to form thicker or heavier portion adjacent the axially 50 extended flange 3, and outwardly extending annular corrugations 4 in the form shown in Fig. 4 with their opposite sides flaring or in inclined relation to each other. I then insert the heat transfer inserts 5 which are substantially rectangular in cross-section bent edgewise into circular form with its two ends abutting as at lb,

. into the groove of corrugations I, and thereafter roll or otherwise press the sides of the corrugations against the opposite sides of the heat transfer insert 5 as shown in Fig. 5, after which the steel supporting shell is placed in a suitable spinning machine where the supporting shell is revolved rapidly and molten metal, such as iron having a sumciently high temperature to produce a plastic film on the inner periphery of the steel supporting shell and to melt the transfer member, is deposited within the rotating steel supporting shell and fused thereto, causing the heat transfer 'inserttobefusedtothewnllsofthsannular corrugations and to the annular groove in spaced apart relation to said flange, a cast metal lining fused to the inner periphery of said shell and a circularly formed 10 heat transfer insert extending into said groove and embedded into the said metal lining.

DONALD J. CAMPBELL. 

